Discovery Launch Set For Nov. 20

CAPE CANAVERAL — The space shuttle Discovery has been given a green light for liftoff Nov. 20 on a classified Pentagon mission to deploy a satellite that will reportedly snoop on the Soviet Union.

NASA managers announced the date Tuesday after completing a safety review at Kennedy Space Center and clearing Discovery for its second flight this year and the first night launch of a shuttle since 1985.

Liftoff is scheduled between 6:30 p.m. and 10:30 p.m., officials said. The Pentagon has ordered the exact time kept secret, but it is believed to be set for about 7:30 p.m.

The mission is expected to end four days later with a night landing at Edwards Air Force Base in the California desert.

Although the military has refused to discuss the flight, Discovery will carry a three-ton electronic eavesdropping satellite for the Pentagon and National Security Agency, the magazine Aviation Week and Space Technology reported Monday.

The satellite will ''ferret out voice, telemetry and other broadcast signals from Soviet military installations'' and will be released from the shuttle's cargo bay seven orbits after liftoff, the magazine stated.